A voyage to the world of Cartesius written originally in French, and now translated into English.

A Letter to M. Descartes.

Monsieur,

I Cannot sufficiently express my Acknowledg∣ments, of the Honours and Civilities I re∣ceiv'd from you, during that transitory Stay I made in your Parts of the highest Heavens: The few good Qualities and Accomplishments, you must necessarily find in me, prevented not your treating me as a Person qualify'd with the great∣est Merit. For you to build an intire World before my Face, and to give your self the trou∣ble of making me comprehend the whole Con∣trivance, to see all the Wheels and Springs of

so admirable a Machine, was an Honour greater in its kind, than what the King vouchsafes Em∣bassadors, Princes and mighty Personages, by com∣manding all the Water-works to be plaid for them at Versailles. You may infallibly reckon from that time, that I am devotedly at your Service; and that having made your self abso∣lute Master of my Vnderstanding, by those sub∣limated Notices you have communicated, you have yet more irresistibly captivated my Will, by those extraordinary Favours you have heap'd upon me.

The Reverend Father Mersennus, who readily condescended to the trouble of this Letter, will inform you more at large, both what my real Sentiments are of your Person and your Do∣ctrin. My Behaviour, since my return, hath throughly convinc'd him, that there never was a Disciple more Zealous than my self, for the Honour, Growth and Advancement of the Sect. In less than a Month, since my Arrival from your World, I have cast Terror and Confusion in the Face of Peripateticism throughout the Land. I have inspirited with new Life and Courage, those few drooping Cartesians that remain'd, but liv'd in Obscurity and Silence, solacing themselves with the private enjoyment of Truth, but were very remiss in promoting her Interest there, where she had been but ill receiv'd. Twice every Week I hold publick Disputes at my House, and indeavour therein, as much as possi∣ble, to give Vogue and Reputation to your Doctrin; I have already made some Conquests among the Peripateticks, many whereof appear there, and excepting two or three, who are un∣governably headstrong and conceited, they will

all be my own, as soon as I shall have answer'd some pretty substantial Objections, they have propos'd against several Points of your Philo∣sophy. The chief of which respect the general Construction of your World. And whereas in that Affair, they pretend to destroy your Con∣clusions by your own Principles, and some a∣mongst them are Men of Parts, that give a spe∣cious and probable turn to their Arguments, in so much that I have sometimes been put to't to find the Fallacy, I thought my self oblig'd to have recourse unto the Oracle, and that I could do nothing better than consult You your self, as you gave me Permission, and intreat you to communicate your Thoughts, as soon as possible thereupon. A Voyage from the third Heaven to this Place, is no great business for your little Moor. Thus then these Gentlemen, to my best Remembrance, fell to Work.

They began by proposing two or three trite Arguments, daily made use of in the Desks, to confute your System; and to shew that it is a meer Chymera, and not to be suffered as a simple Hypothesis, should they grant the Principles you your self lay down. M. Descartes (say they) supposes, first, That God creates Matter; se∣condly, That he divides it into infinite little cubical Parts, and lastly, determining several great Portions of this Matter, he puts them in a circular Motion, and at once makes the little cubical Parts, of which the great Portions, call'd by him Vortexes, are compos'd, to turn about their proper Center. But it is impossible, they adjoyn, to conceive the division and motion of Matter upon his Principles.

For•• as to the division, it can be conceiv'd but by one of these two ways; either by supposing betwixt the Parts divided some empty Spaces, or imagining those Intervals fill'd up with some Bodies or Matter of a different Nature from the Parts. And thus though Nature every where is full, we conceive four Dice laid close to one another, as four distinct cubical Bodies; for though there is nothing of a void betwixt them, we yet perceive a little Interval fill'd with Air, that hinders our Conception of them, as of one single Body: But by the Principles of Cartesi∣anism, we can conceive it neither one way nor the other. For we must not suppose a Vacuity betwixt the Parts divided, since a Vacuum is ut∣terly thrown out of that System. Nor is it easier to conceive a Body of a different Nature, since the distinction of Bodies, according to the Author of the System, is not to be conceiv'd, till after the agitation and motion of Matter. That division therefore is an Absurdity.

As to the business of Motion, that's in a worse Case still; for how is it possible to conceive that all those cubical Parts, that are universally hard, impenetrable and incapable of Compression, should turn about their Center, and break in pieces, unless they find or make a Vacuum? For the diminutiveness of them will not help us out, since let them be as little as you can sup∣pose them, they are still hard and impenetrable as Adamant, and all combine together to desist the Motion of each Particular. That Hypothesis therefore is indefensible, and Descartes his very first Supposition is deny'd.

These, Monsieur, were the first Passes these Gentlemen made at me, the first Blows I was to ward off, in the Defence of the System of your World. They had been taken out of the Books of very Ingenious Men; and whereas the Gentlemen, your Disciples (as if it was their Maxim and their Method, never to be put out of their own Road, which is barely to give an Exposition and a Proof of their Doctrin) trouble not much their Heads with Objections that are made them, since they are not oblig'd to the formal Answer of the Desk; these Argu∣ments pass'd for unanswerable, and such as at the very entrance of Dispute baffled the Cartesi∣an. But the more impregnable my Adversaries appear'd in so good Accoutrements and Arms, the more my Honour was advanc'd in disabling and disarming them.

As I had diligently read your Works, and above all, the Book of Principles, and that In∣titled, a Treatise concerning Light, or M. Descar∣tes's World, I answer'd the first Argument, by pleading a false Indictment charg'd on you, for making a distinction of Instants betwixt the Division and the Motion, as if you had held that God divided the Matter in one Instant, and mov'd it another: I said you never suppos'd that Matter was divided before its Motion: That the manner of proposing your System in the third Part of Principles, suppos'd no such di∣stinction, and that in the Treatise of Light, where you describ'd the formation of the World, you said positively the contrary; advertising your Reader, That that Division of Matter consisted not in God's separating its Parts, so as to leave a Vacuity betwixt them; but that all the di∣stinction,

you suppos'd God made in them, consisted in the diversity of Motions that he gave, causing some from the first instant of their Creation to commence their Motion one way, some another; so that in this Instance Division and Motion were the same Thing, or at farthest one could not be without the other. That you would be as forward as any of them to confess, That nothing was more absurd, in reference to your other Principles, than to suppose the Parts of Matter still and in Repose, and yet divided, since, according to you, the Union of the Parts of a solid Body, such as Matter must be con∣ceiv'd before its Motion, consists in that Rest they enjoy by one another: And farther, that it was full as easie to comprehend how Division was made by Motion, and yet cotemporary with the same Motion, as to understand how I can tear a Sheet of Paper, by dividing it in two half Sheets, one whereof I hand towards the East, the other towards the West. I hereupon pro∣duc'd the Books that I had cited, and shew'd them the very Places in dispute: They were convinc'd by plain Matter of Fact, and had no more to urge against it.

But we had not so soon done with the Motion of Matter; we must necessary still dispute, tho' very calmly, without the least Passion or wrang∣ling, since the generality of those I had to deal with were well bred, honest Gentlemen, that would submit to Reason. The Question was, to explain, how the Parts of Matter, which we con∣ceiv'd so closely press'd against one another, as not the least Interval was left betwixt them, throughout the Mass, and which we also suppos'd solid, from a settl'd Rest could skip into Motion.

After these Gentlemen had copiously discours'd upon the Subject, I ask'd them, If as stanch Pe∣ripateticks as they were, they were throughly convinc'd, that the Fludity of Water, for instance, Was an absolute Quality, that when it was congeal'd it became Solid, by an absoute Ac∣cident, call'd Solidity, and that when it was dis∣solv'd, it became Liquid by an absolute Accident call'd Fluidity? That one of these Accidents made Lead run when heated, and the other fixed it when it began to cool? And on the contrary, if having read the Delicate Natural and Intelligible Way of M. Descartes's explain∣ing the Nature of Fluidity, and the Properties of Fluid Bodies, by the Motion of the insensible Parts of those Bodies (a Motion which the meer Dissolution of Salts in common Water, and of Metals in Aqua Fortis evidently demonstrates) they were not at least come over to us in that Point? The most of them answered, That as they were persuaded there was no doing without absolute Qualities, in the explication of an abun∣dance of Phenomenas, that which they could most easily part with was Fluidity, and that they would not quarrel with me thereupon.

This suppos'd (said I) Gentlemen, you shall be speedily satisfied, or more perplex'd than M. Descartes; for in short, in your own System, the World is full, there's an Abhor∣rence of a Vacuum through the whole: Motion, notwithstanding, both is and does continue, the Sensible and Insensible Parts of Bodies are mov'd, nor does their Hardness and Impenetrability stop their Progress. Why may not M. Descartes's Matter, that is no more impenetrable than yours, enjoy the same Priviledg and Charter? Why

must his Motion be more impossible? both you and us suppose the self•• same Thing, and we have no more to do than defend our selves against the Epicureans, who think they demon∣strate by Motion, the Necessity of their little insensible Vacuities interspers'd throughout all Bodies. Their pretended Domonstration amounts to this; To the end a Body may move, it is ne∣cessary it disturb another Body from its Place: That other cannot stir, because it has not where to go, if all is full: Therefore Motion will be impossible, if there is no Receptacle or a Vacuum. On the other Hand, supposing a Vacuum among Bodies, they may be compress'd in lesser Room, and consequently may make Way for such as press against them; and thus Motion will be made. This is a meer Fallacy of theirs, which both you and we can easily unriddle, by only telling the Epicureans, That to conceive how Motion is perform'd without a Vacuum, we need only understand, That a Body is never mov'd alone, but that in the same Instant one Body quits its Place, another crowds in and takes it: And when I conceive one Body may in the same Moment take the Place another Body leaves, I perfectly conceive Motion, for there lies all the Mystery.

My Peripateticks seemed surpriz'd to see me come over them thus readily, with so neat a Conclusion, drawn from a Principle they had so freely granted me, and doubtless repented them of their Condescention: But I proceeded, by telling them, I scorned to take an Advantage over them from their Courtesie, though they were oblig'd to it by the Evidence of the Truth, and I was unwilling they should reproach me,

as perhaps they did already in their Hearts, for having us'd Surprize, and abus'd their good Nature to insnare them; and therefore I would endeavour by their own Principles to enforce to them, at least the Probability of the Truth I was defending.

Gentlemen (said I) there are Prejudices in the Case that we are upon, proceeding from the Imagination more than Reason: We imagine, in the first Place, That a Body which we fancy in the midst of the Matter of the World, is far more press'd, if we suppose that Matter Solid, than it would be upon Supposition it were Fluid, which is manifestly false: For if the World be full, whether with Solid Matter or with Fluid, there is neither more nor less of it, but an equal Quantity in each Supposition; and consequently its Parts are no more close and crowded, sup∣posing it Hard than if you suppose it Fluid. Again, we are apt to believe, That a Body, whilst it is Liquid, is ever ready to give way to the Motion of another Body; and on the con∣trary, whilst 'tis Solid, it is incapable of that Com∣pliance, if incompassed with other Solid Bodies. The first is prov'd evidently false, by a very common Experiment: Fill a Glass Bottle with Water, whose Neck is long and slender, then turn the Mouth of it downwards, placing it per∣pendicularly upright, the Water by its own Weight is forc'd towards the Earth, it meets no other Body in its Way but Air, that is still more Liquid than it self; yet notwithstanding the Gravity and Propensity of the Water to put itself in Motion, notwithstanding the Fluidity of the Air that is below it, its Motion is impossible, and the Air makes as great an Opposition as could

a Solid Body, wherewith you should have firm∣ly stopt the Orifice of the Bottle: What is it then that thus obstructs the Motion of the Wa∣ter? 'Tis the Air and Water's being in such a Situation, as no Tendency or Attempt what∣soever of the Water can determine the Air, or any other Body, to come and fill its Place in the same instant that it leaves it: For as soon as it can, that is to say, as soon as you shall incline the Bottle a little Side-ways, and consequently make Way for a little Line of Air, to wind it∣self in by the Side of the Water, the Motion will follow proportionably to the Space that the Air shall fill. We must not then suppose that a Liquid Body is ever disposed to yield to the Motion of other Bodies: Nor ought we more to imagine, that when a Body is Solid, and surrounded with other Solid Bodies, it never is inclinable to be mov'd, which I thus prove.

Let us suppose an hollow Globe perfectly full, partly with Water, and partly with a vast many little solid Bodies, of every Make and Figure, dispers'd all over this Mass of Water. Let us conceive all these Bodies settled and at rest; be∣ing that the Water fills all the Spaces betwixt these little Bodies, we imagine the Parts of this Water of all sorts of Figures, as are the Spaces which they fill. Thus we conceive in those Spa∣ces your little Globes of Water, little Triangles, little Cubes, little Hexagons, &c. Let us suppose now, that Water and all those little Bodies put in Motion.

Making then Reflection on the Figure of the Parts of this Water, before the Motion, we ea∣sily conceive an Alteration in all these Figures, in the instant of Motion; that is to say, the

little Globes of Water are divided in two half-Globes, the Cubes of Water lose their Angles, and so on. Of these little Parts, whether Solid or Liquid, some receive more Motion, some less, and briefly all so determine one another, as not the least empty Space is left, but upon one's for∣saking of a Place another repossesses it in the very instant: And all this is easily perform'd by the proneness of the watery Parts to break and disengage themselves from one another. Thus in the first instant of the Motion, we ima∣gine that there happen'd a Change of infinite Fi∣gures; that this Change was made only by the Fraction or Separation of the Parts; that that Fraction was occasion'd by the Motion, and that the Motion was impossible without that Fraction: That the Impulse that serv'd to put these Bodies in Motion, was the Cause of both the Motion and Fraction: That the Fraction of a Part was caused immediately, whether by one of the Solid Bodies, or by another part of the Water; for instance, the Angle of a Cube was no otherwise separated from the rest of the Mass, or any other Part to which it was joyn'd, than by another part that slipt in betwixt them both, or so ex∣actly seiz'd its Place, as to fit it to an Hair; and finally that nothing could prevent the Moti∣on and Fraction of the Parts, except such a Situation among themselves, as rendered it impossible for one Part to take the Place of another in the Moment of Desertion; For all being full before the Motion, it is neces∣sary in the Motion all remain full still.

Let us suppose at present, all this Water and all these little Bodies restated in the same Con∣dition they were in before the Motion: And let

us conceive instead of the parts of Water, that possess'd all the Intervals betwixt the solid Bo∣dies, some other solid Bodies that precisely take up the same Space the Watry parts took up be∣fore: Or let us only suppose the Water con∣geal'd, but without any diminution or augmen∣tation of its Mass. Let us farther suppose, that God made an attempt to move this Matter; and that he indeavour'd at once to divide all its parts exactly in the same manner as the parts of Water, whose place it fills, were divided in the instant of their Motion. I suppose not any Motion yet, but only an Effort for the produ∣cing it, and there's no Contradiction in that Effort: But I maintain, that from that Effort or Attempt, Motion and Fraction must inevita∣bly follow: And thus I argue.

From that Attempt which I suppose, Motion and Fraction must needs follow, if nothing hin∣ders: But nothing hinders: For the disposition to Motion and to Fraction is the same in this Hy∣pothesis, wherein I suppose nothing but solid Bodies, as it was in the foregoing, wherein I suppose liquid Bodies mixt with solid ones; and if the repugnancy to Motion and to Fraction, which some imagine in the latter, be invin∣cible, it would be invincible in the former too.

For if in the first Hypothesis of liquid Bodies mingled with solid ones, we imagine the parts so crowded and determin'd, as that one going to move another is unable to gain its place, in the same instant we imagine that the Motion and Fraction of parts can never be: As it hap∣pens in the Experiment of the Bottle before mentioned: Because an absolute fulness being

suppos'd, all the parts combine in the resistance of the Motion of each Particular: But whilst we conceive the parts of this Matter so push'd and determin'd, that supposing one to move, another in the same Instant takes its place, and another the place of that; thus we conceive Motion and Fraction infallibly must follow the Impulsion. But in the second Hypothesis of solid Bodies, supposing God to force and determine the parts of those Bodies precisely in the same manner, as the Parts of Water had been determin'd in the first Hypothesis, at the first instant of Motion and Fraction; it is plain, that in case one move, another must instantly take its place, since it is exactly driven and determined, as the parts of Water was that took that place. Therefore Motion must follow in the second Hypothesis as in the first.

All the difference lyes in this, that the parts of Water being with the greatest ease imagina∣bly divided, but a very inconsiderable force is required to move them; and the parts of solid Bodies being more difficult to be divided, a far greater impulse would be required to do it: But M. Descartes has liberty, if he pleases, to suppose this Infinte; and that resistance which God would find, would not be of all the parts in general, against the division of each in Parti∣cular; a resistance we find insurmountable in Plenitute that's fluid: But would only be the re∣sistance of each part against its own Division, which we can most distinctly conceive not to come up to invincible.

In a word, the Motion and Division of solid Bodies is possible in Pleno, whilst we conceive the different parts of these same Bodies push'd to∣wards

all parts imaginable of the Space, and so determin'd that upon one's Desertion of a place another immediately fills it: For without this Proviso, Motion is impossible even in Fluids, and with it, it is necessary though in solid Bodies.

Although, said I unto them, this Explication seems to me a true Demonstration, yet I pre∣tend not to recommend it unto you as such. I am satisfied if it only staggers your Opinion of the certainty of the contrary Arguments, ordi∣narily made use of in this matter; and I questi∣on not but, that after you have considered it with Attention, you will grant me more than at present I demand.

In effect my Academicks seem'd well enough satisfy'd with what I said; scarce above one Scruple more stuck by them proceeding from a Supposal of theirs, that in the first Instant of division you gave a cubical Figure to all the parts of Matter. A Circumstance that still blunted their Imagination. To this I answer'd, that would they but reflect on what I had been ex∣plaining to them, they would clearly perceive that Circumstance made no particular Difficulty; but throughly to dispossess them of all uneasi∣ness, I assur'd them, you never had made that Supposition, as your own Words might easily convince them; that in your Book of Principles, you suppose no more than this, That all the parts of Matter were not Spherical; and that in your Discourse of Light, you give them all imagina∣ble Figures: I farther shew'd▪ them the places, and brought them to confess the little Honesty or Exactness of some Authors, who thus adap∣ted the Exposition of your Doctrin to their Phancy, and the way that lay most advantagious

to attack you in. Lastly, in two or three Words I gave them your own Thoughts and Sense thereupon, which I always took to be the same with this, viz. That God in the first agi∣tation and division of Matter, reduc'd it into all kind of Figures, which he forc'd and deter∣min'd every way towards all sides of the Space: That he thereby made a liquid Body; great Portions whereof he after took to move them circularly and make Vortexes, wherein the gene∣rality of the insensible parts that constitute them, turn'd round about their Centre; that by this Motion there was made a continual change in the parts of Matter, some losing their Angles, others uniting and linking themselves to one another. That I, after you, believ'd the same thing happen'd every moment among the insen∣sible parts of all liquid Bodies; and thence it was that you infer'd the Existence and Distin∣ction of your three Elements. I flatter my self Monsieur, you will not be much dissatisfy'd at my Answers, and that you will acknowledg that how far soever I am behind-hand with the rest of your Disciples in Parts and Penetration, there are but few that exceed me in the Attention you desire your Readers to bring with them in en∣tring on your Books, and Application requisite before they pass their Judgment, and especi∣ally before they venture to oppose them or de∣fend them.

But to persue in giving you the Account of my Conferences: This I have been mentioning had two Effects. The first was to break a little our Peripateticks of that mischievous Opinion, they had admitted of your Doctrin, which they had till then regarded as full of Contradictions

and Absurdities, absolutely incapable of De∣fence, and as a System that undermin'd it self. The other was, to cause two or three of the most subtil and discerning of them, to apply themselves closely to the reading and examina∣tion of your Books; whereby they have found Difficulties in earnest, that seem to me to be truly so, and upon which, as I at first observ'd to you, I was forc'd to make my Appeal to you your self. For I must confess that as Haughty as I was, upon my first Success, I am now re∣duc'd to such a Maze, as makes your Light and Assistance necessary to extricate me the••ce.

'Tis now a Fortnight that these Gentlemen have desisted to urge any thing against your Do∣ctrin; and three or four Conferences in the Interim have pass'd in the explaining your Sen∣timents, and resolving some Questions they pro∣pos'd to me, upon several particular Passages of your Books, of which they thought, at least pretended that they thought, they did not rightly take the meaning. This was only a Stratagem they made use of to trapan me. I was well aware of that petty Conspiracy, which doubtless would have given me some disturbance, having to deal with Men of admirable Sense, had not the goodness of the Cause I manag'd, bore up my Courage and Resolution. To con∣clude, two Days since they brav'd it at an high rate; and promising or threatning in a short time, to confute the greatest part of your Me∣taphysicks and your Physicks, they told me they would immediately fall aboard the System of your Vortexes: That that was to attack you in the main part; and they question'd not but

they had upon that Article, wherewith to ruin your Physicks to all Intents and Purposes.

Notwithstanding, whereas they are as Court∣ly and Obliging, as Ingenuous and Judicious, and besides were well persuaded of the difficulty of their Arguments, to save me that Perplexity and Confusion, in the trouble they foresaw I should be put to, in giving the Solution, they would not oblige me to answer them on the place: But were content to give them me in Writing, that I might return my Answer at my leisure: They only read them over to me, to see if I comprehended their Sense; and I pro∣test to you, though I seem'd to Vapour, I was extraordinary pleas'd in my Mind, with those little Differences which they paid me: For they argu'd only from Matter of Fact and Prin∣ciples drawn Word for Word out of your Books, which they turn'd one against another, and made them destroy themselves in so plausi∣ble and probable a manner, as requir'd M. Des∣cartes himself, at least one better skill'd than I am, to refute them. I shall transcribe the principal things of their Memoire, and in their own Ex∣pression. They have given it this Title.

Objections offered a Cartesian by some Peripateticks, against the general System of M. Descartes's World.

FIRST, they pretend to prove that the Posture and Array in which M. Descartes has marshal'd his Matter, or his three Elements in his Vortexes, thwarts and contradicts his ge∣neral Rules of Motion, which he gives himself, and the Properties he attributes to every of those Elements. And thence they'l draw such Consequences as intirely overthrow his Doctrin touching the Nature of Light.

Secondly, they will shew that his manner of explaining Light is no ways consistent with (not to repeat his Position of the Elements in the Vortexes, but) the very disposition of his Vor∣texes amongst themselves.

Thirdly, they will prove, that by the Prin∣ciples of M. Descartes, the Earth, no more than any other Planet, can be priviledg'd with a Pe∣culiar Vortex in the Vortex of the Sun. Which being once more Demonstrated, all M. Descar∣tes's Astronomy is turn'd topsy-turvy, and the whole OEconomis of his World utterly routed and destroy'd.

The first Argument.

1. We forthwith take for granted, that Master-Principle of M. Descartes, That every Body circularly mov'd constantly endeavours to eccentrick it self, and escape from the Circle it describes.

2. From that universal Principle immedi∣ately follows this particular Consequence, that in a Vortex, where the Matter of the first, se∣cond and third Element are circularly mov'd, all three endeavour to acquire a Motion eccen∣ctrick to the Vortex.

3. We infer yet farther, from the same Prin∣ciple, another Conclusion, That in that general Attempt, made by different Bodies thus agita∣ted and confus'd, to deviate from the Centre of their Motion, those that are most agitated and are most fit for Motion, those, I say, must have the advantage and ascendent over the rest, to gain the Circumference of the Circle the Vortex describes, and consequently to compel the less agitated, and less fit for Motion towards the Centre of the Vortex.

Though this Conclusion should have no visi∣ble and necessary Connection with the Princi∣ple, as indeed it has: Yet we might warrant our use of it, by producing M. Descartes to vouch the same thing, in several places of his Books, and particularly in his fourth Part of the Book of Principles. Where he gives the reason for the Motion of heavy Bodies towards the Centre by this same Proposition.* 1.1 That it was by vertue of that Principle, that in the Vortex

of the Earth, Terrestrial Bodies are below the Air, and the Air below the Celestial Mat∣ter.

To these we only add one more that M. Des∣cartes frequently repeats, especially in the third and fourth Part of Principles, and in the eighth Chapter of his Tract of Light, viz. That the first and second Element have much more agita∣tion, and are far more fit for Motion than the third, whose parts are ragged and branchy, and of a very irregular Figure.

All this suppos'd, let us agree with M. Des∣cartes, that Matter having been created such as he advances, God was able to divide, and actuate it with Motion, and that he effectively has di∣vided it and mov'd it. Let us stop now, and fix our Imagination and our Thoughts upon that great Partition of Matter, or upon that Vortex, that hath the polar Star for its Centre. Let us con∣ceive that portion of Matter, made up of an in∣finite number of little insensible Parts it self turn'd round, whilst all the little Parts are also turn'd about their proper Centre.

From this Motion must arise the three Elements, that is, the most exquisitely subtle dust of the first Element, the little Balls of the second, and the ramous Parts of the third, all which are Parts of the same Matter differing from one another meerly by their Figure and their Bigness.

Whether the third Element be cotemporary with the other two, as M. Descartes seems in some measure to suppose in his Treatise of Light: Or, whether it be form'd by the Conjunction of seve∣ral Parts of the first Element hook'd to one ano∣ther, as he seems to teach in the Book of Princi∣ples: That Philosopher pretends, that in that

justling and concussion of Matter, when it hath lasted long enough to break the Angles of most of the agitated Parts, the Matter of the first Element must be posted in two principal places. First, in the whole Space of the Vortex, where it ought to be dispers'd, to fill exactly all the Intervals found betwixt the Balls of the second Element, whereof the whole Substance of the Vortex or the Heaven is compos'd; Secondly, at the Centre, whither it must be forc'd by the Balls of the second Element to descend, to consti∣tute a Spherical and Fluid Body, which is no∣thing but the Star it self, that by the circular agitation of its Matter, and the struggle that Matter makes to procure its Inlargement from the Centre of its Vortex, thrusts the Globules of the second Element that is above it, to all Points imaginable, and communicating by their means that Impression to our Eyes, produces in them the sensation of Light.

This is the Sum of all M. Descartes's fine Do∣ctrin on this Subject. But we offer to demon∣strate to him, by the aforesaid Principles, which are all his own, that it is not the Matter of the first Element, but the third that ought to consti∣tute the Centre of the Vortex; and thus the Stars must not be luminous, nor the Sun any more than they, but all must be opaque Bodies, as are the Planets, the Earth, and solid Masses com∣pos'd of the unactive and almost motionless Parts of the third Element, entangled and link'd with one another.

The Demonstration.

When several Bodies or Parts of Matter are circularly mov'd together, those which have the least Agitation, and are least dispos'd for Moti∣on, are the least able to make their escape from the Centre. And on the contrary, those that have most agitation, and are best dispos'd for Motion, are most able to make their escape, and compel the other downwards to the Centre. This is the third Principle I have suppos'd, after having deduced it from M. Descartes.

But the Matter of the first and second Ele∣ment have much more agitation, and are ex∣ceedingly better dispos'd for Motion than the Matter of the third. This is the fourth Princi∣ple which M. Descartes constantly supposes.

Therefore the Matter of the third Element, not that of the first, ought to take up the Cen∣tre of the Vortex. Which is the Proposition to be demonstrated; and is contradictory to that of M. Descartes, on which he founds his whole System concerning Light. Therefore the Sun and Stars must be dark, not resplendent Bodies. We charge nothing upon him here, but what is expresly his own; and we demand at the same time by which of his Principles, not knowing what to do with the Fragments of the blotches of the Sun, nor what use to put them to at the Centre, or near the Centre of the Vortex where they are gathered and dispersed, he makes them wrest and force themselves in to the midst of the Circumference, as branch'd and incapable of

Motion as they are; and constitute a sort of Air, which, according to him, is extended as far as the Sphere of Mercury or farther? How comes it to pass that the first or second Element,* 1.2 that are either at the Centre or near the Centre, or immediately below these broken parts, resign so patiently the right they have by Vertue of their vehement agitation and proneness unto Motion, to the place the others get possession of towards the Circumference? And if once that irregularity and disorder, so opposite to the Laws M. Descartes hath establisht in his World be tolerated towards the Sun; why must a Stone that near our Earth shall be cast into the Air be violently retorted towards the Centre, by the Matter of the second Element below it, under pretence that the Stone hath usurp'd a place unbefitting its Quality, and only due to the Matter it hath displac'd, on account of its vehement Motion?

And thus it is that M. Descartes's Principles agree. Thus he is so very frugal as to make them serve for several purposes, even for con∣tradictory Conclusions, with the assistance of some little Comparisons he can well enough ma∣nage, to the blinding those that read his Works but carelesly, and are commonly design'd for nothing but to disguise his Paralogisms, and put off his Propositions that Reason cannot justify.

The second Argument.

In order to comprehend this Difficulty, we must suppose with M. Descartes, that all the fix'd Stars are not contain'd in the Circumfe∣rence of the same Sphere, nor equally distant from the Centre of the visible World. That some are sunk deeper in the vast Spaces of the Firmament, others dive nearer to the Centre of the World. We must also remember that each of them have their proper Vortex, of which they are themselves the Centre, and that those Vortexes are so many different Spheres rang'd above, below, and on the sides of one another. As for Instance, we must conceive the Vortex of the Sun, in which floats our Earth, with the other Planets, as a fluid Sphere, surrounded with many others like it, which it touches in several points of its external Superficies, just as a Bowl incompass'd on every side with other Bowls touches them all in different parts of its Circumference.

[illustration]

S The Vortex of the Sun.

In the third place we must recollect M. Des∣cartes's manner of explaining Light, which con∣sists in that endeavour the Matter of the first Ele∣ment makes at the Centre of the Vortex, to get farther from the Centre, whence, pressing on the Celestial Matter, or the second Element in all imaginable Points, that impulse and that

pressure light on all the Lines that reach to the Circumference of the Vortex; some of which necessarily falling on our Eye, when directed to∣wards the Star or Sun, make such a Pression and Vibration there, as determine our Soul to that Perception which goes by the Name of Vision.

[illustration]

This Figure will easily explain it, where the little Points at the Centre of the Circle repre∣sent the Matter of the first Element, or the Body of the Star. The Lines drawn out to the Cir∣cumference, represent the Celestial Matter, whose Rays concenter in the Eye plac'd at the Circumference of the Vortex.

We presume to affirm, That in this Situ∣ation of the Vortexes, we who are in that of the Sun should not be able to see the Stars, Monsieur Descartes's Principles suppo∣sed.

Let us add to the preceding Figure, four other Vortexes, supposing them the Vortexes of four Stars that are nearest to that of the Sun.

[illustration]

Let the Eye, plac'd in the other Figure to be∣hold the Sun, be turn'd towards one of these Vortexes, to behold, for Instance, the Star B. wee'l demonstrate by M. Descartes's Principles, that it is not possible to be seen.

The Demonstration.

The Eye can no ways obtain the sight of the Star B, but by means of the Rays or Lines of the Celestial Matter, push'd by that Impulse the Star B. causes in strugling to get from the Centre of its Vortex, which Impulse is communicated to the Eye, by its pressure and concussion of the

Strings of the Optick Nerve. But this is impossi∣ble, supposing the Eye placed in the Vortex of the Sun. And thus we prove it.

That Impulse must be communicated to the Eye by one of these two ways; either immedi∣ately by a Ray, or Line of Matter drawn from the Vortex of the Star and Terminating in the Eye; or mediately by a Line of the Solary Vor∣tex, in which the Eye is plac'd, retorted on the Eye by the Vortex of the Star. As if the Line B, A. of the Stellary Vortex, should retort upon the Eye the Line A. C. of the Solary Vortex. For it is impossible to conceive the Star should cause any Impression on the Eye but by one of these two ways: But neither the one nor the other will serve our turn.

Not the first, because the Vortexes, according to M. Descartes, have each their circumscrib'd and separate Sphere of activity, and a Motion altogether different. Insomuch that the Lines of the one are never blended with the Lines of the other: But end severally at the Circumfe∣rence of their own Vortex; and if once that Communication or rather Confusion should be admitted, all would speedily return, into that confus'd and disorderly Chaos, from which M. Descartes will have his World extracted, by the only Laws of Motion; and farther, since there is no point in the Vortex of the Sun, wherein we cannot see the Star, the Matter of the Stars Vortex must necessarily possess all the Space of the Vortex of the Sun; than which no∣thing can be more absurd.

There remains the second way, which will prove as useless as the former to M. Descartes, proceeding on his Principles; forasmuch as with

him the Vortexes, though unequal perhaps in Big∣ness, must be ever equally matcht in Power and Efficacy. For, says he, unless there was that equality betwixt them, they would infallibly destroy each other. Now that equality pro∣ceeds from this, that the Star of a Vortex mov∣ing still uniformly round, presses the Matter of its Sphere towards the Circumference, and a∣gainst the neighbouring Vortexes precisely with so much force as the Stars of the other Vortexes press the Matter of their Sphere in opposition to it. Which is the reason, according to him, that they always maintain their Ground against each other: But from hence also we manifestly conclude, That the Matter of one Vortex is in∣capable of repelling that of another, or causing it to recoil towards the Centre, from whence it struggles and contends to move with all its force, reliev'd also with the whole Posse of the Star that pushes it. Therefore that Effort, the Mat∣ter of a Star makes to get farther off the Cen∣tre, can make no Impression on our Eye, so long as it is in the Solary Vortex; since the com∣munication of that Impression is utterly pre∣vented by the Matter of the Solary Vortex, that with all its might and main resists it, and con∣sequently hinders that pressure on the Organ, which is the only cause of Sight. To explain our selves by a comparison much like that so of∣ten made use of by M. Descartes. Let us sup∣pose a blind Man, whose Hand stirring neither one way nor other, touches the end of a Staff. Let us again suppose his Hand so capacitated and dispos'd, that for the Perception of the Staff it is not sufficient that it be immediately con∣tiguous to it, but that there be besides that Con∣tact,

some pressure of the Staff against the Hand. Let us in the third place suppose another Hand, pushing it strongly against that of the blind Man. Lastly, let us suppose that a third Person, holding the Staff in the middle, indea∣vours to withhold it from the Hand of the blind Man, and that this indeavour be exactly equal to that the second Hand makes the contrary way. In this case the Staff, will advance neither one way nor other, it will make no pressure on the Hand of the blind Man, and consequently, according to the first part of the Supposition, he will not be sensible of it.

[illustration]

Let us apply this to the Case in Dispute: We will imagine a Line of Celestial Matter reach∣ing from the Eye to the Circumference of the Solary Vortex. The immediate Conjunction of that Line with the Eye is insufficient to produce

the sensation of Light, unless something more be added. That then which must be added, is an impulse and pressure of that Line against the Eye, which will determine it to see; and this is the Doctrin of M. Descartes. But now whence comes that pressure in the Hypothesis before us? It cannot proceed precisely from that Line of Celestial Matter, seeing it makes a directly con∣trary Attempt, to withdraw it self from the Eye towards the Circumference of the Solary Vortex. It must then, if at all, proceed from the Line of the neighbouring Star's Vortex, that reflects the aforesaid Line against the Eye. But this making as forcible an Attempt to get from, as that to press it on the Eye; it is plain, that Effort and Impulse can no more reach the Eye, than can the Effort of the Hand that pushes the Staff, arrive to the Hand of the blind Man; and that the Eye admits no pression from the Cele∣stial Matter requisite to cause the Perception of Sight: Like as the blind Man's Hand receives no Impression of the Staff, requisite to excite the Sense of Feeling, or to cause the Perception of the Staff; and consequently the Eye, plac'd in the Vortex of the Sun, will be as far from seeing the Star, as the blind Man from feeling the Staff.

But for a Confirmation of all this, we must remember, that in the Principles of Descartes, not only what interrupts that Effort and that Pressure, but also what ever weakens or curtails one or the other, consequently frustrates the effect of the luminous Object on the Eye; and thus it is that Philosopher explains the spots of the Sun, or those defailures of Light, that appear in several parts of the Convex of that

Luminary. For, according to him, the parts of the third Element, hookt and ingendred with each other on the Surface of the Sun, keep the Matter of the first Element, of which the Sun is made, from pushing the Celestial Matter to∣wards my Eye, with so much force as formerly: Which is the reason that the Lines of the Ce∣lestial Matter, which touch my Eye, and which we suppose extended to that Matter of the third Element flak'd upon the Body of the Sun, are no longer Rays of Light, that should represent to me that part of the Sun as bright as all the rest. So that the Light, which I perceive in all the Sun besides, causes me to perceive in that part of the Sun a defect of Light, which we call a Spot or Stain. Now it is evident that this Portion of Matter of the third Element, that only floats upon the Surface of the Sun, breaks the force, wherewith the Matter of the Sun pushes the Celestial Matter against my Eye, much less, than if a force equal to that of the Matter of the Sun stood determin'd, and fully bent against it, as it happens in this Case, where the Matter of the Solary Vortex with∣stands the Effort of the Star, and consequently hinders it from making any Impression on my Eye. And here let M. Descartes shuffle and cut, and make what stir he pleases to recover his Reader, by an Explication of Refractions made in the Rays of the Star, upon their passage through the Vortex of the Sun; his only Design is to lurk and secure himself in that Darkness and Obscurity with which he purposely benights the Question. Let him only tell us what he means by those Rays of the Star that arrive to the Earth athwart the Solary Vortex. But what

we have said will sufficiently evidence, how groundless and trifling will appear whatever shall be urg'd thereupon.

[illustration]

But if it be impossible to conceive the commu∣nication of the Effort and Impulsion of a Star, whose Vortex immediately borders on the Suns, what will become of the other Stars, whose Vortexes are infinitely distant from that of the Sun, and which must make a sensible impression on our Eye across a great many Vortexes, whose Matter is differently mov'd, and are all so many Obstacles to that Communication? Doubtless, though all we have been urging amounted not to a Demonstration, in respect of the Stars situate near the Sun, it would infallibly, in respect of all the other. So that instead of those infinite Stars, we see sparkling in the F••rmament by night, we should not discover an hundred with the best Perspectives.

What now if we should add it were impossi∣ble to see the Sun it self? Yet this may be prov'd by the same Principles; for no more is requisite for this, than that the Earth should have a particular Vortex, whose Motion should equalize and resist that of the Celestial Matter which the Sun pushes towards our Eyes. But so much is true, according to Descartes himself; for he expresly teaches, That the Earth hath a particular Vortex, whose Matter struggles as much as possible from the Centre. That effort is contrary to the effort of the Matter of the Solary Vortex on that side which is inlightned by the Sun. That effort is equal to that of the Matter of the Sun: Otherwise the Vortex of the Earth would run to ruin. Therefore the Im∣pression of the Sun cannot be communicated to our Eye.

What shall we say of the Planets and Comets, which are seen by the help only of the reflected Rays of the Sun, and that consequently are not so strong as if they were direct? If the Earth's Vortex, arguing on Descartes's Principles, is able to obstruct the latter, how much easier is it to ob∣struct the former, and hinders us from seeing all those Stars?

All this seem'd very difficult; and before we turn'd Cartesians, we had a mind to be satisfy'd thereupon. But one thing yet remains, and perhaps something better than ordinary, upon the particular Vortex of the Earth, which is Matter of a third Difficulty in us.

The third Argument.

This third Difficulty is well grounded on M. Descartes's Principles, and brings such weighty Consequences against the System of his World, as though all the rest were insignifi∣cant, would alone unravel the finest Contexture in it. He supposes the Earth to have a Vortex particular to it self in the great Vortex of the Sun. A Priviledge also he confers on Iupiter, but denies the Moon. He explains this Suppo∣sition in a plain and very familiar way, exem∣plifying it by those great Whirl-pools we some∣times see in Rivers. In the midst of these great Whirl-pools there are several little ones, that at∣tend the Motion of the bigger, and are carryed round their Centre, and at once whirl Chips and Straws about their own. Nothing could be bet∣ter thought on for the making us understand how the Earth and Iupiter, when carried about the Sun by the Matter of the Grand Solary Vor∣tex, at the same time cause the other Planets to circuit about themselves; how the Moon is forc'd about the Earth, and four little Planets a∣bout Iupiter. But as Ill-luck would have it, ex∣amining that Hypothesis by the Principles of our Philosopher, we found it absolutely impossible.

[illustration]

The Demonstration.

Either the particular Vortex attributed to the Earth is the same with what it had, whilst yet it was a Star; or else it is a new one, made since the Destruction of the other. We maintain that neither the one nor the other can be said. Therefore it can have none at all.

It cannot be that it formerly had. For 'tis M. Descartes's Position that a Star degenerates into a Planet or a Comet, by the loss only of its Vortex. According to him, a Vortex is pre∣serv'd meerly by its Matter, having as much Motion and Resistance as the Matter of those a∣bout it; and its Matter loses that equality of Motion and Resistance, when the Star at the Centre can no longer communicate so much by

reason of the Scum that covers it. Now the Earth is a Star not only covered with a Scum or Dross, but with several thick Crusts of an un∣accountable Depth. So that it was incapable of preserving its Vortex, which must have been quite and clean destroy'd, and swallow'd up (as M. Descartes's Latin Word expresses it) by that of the Sun. Let us see then if the Earth was able to procure a new one since its removal near the Sun.

[illustration]

S the Sun. T the Earth. A B C D the little Vortex of the Earth. N A C Z the great Orb wherein the Earth is carried round the Sun.

M. Descartes takes this same course to com∣municate hi•• Thoughts: He makes this Figure which represents the Vortex of the Sun, in which the Centre S is the Sun it self. The little Circle or Ellipsis design'd with C. D. B. A. represents the

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Matter which carries the Planet round the Sun moves far swifter than the Planet. He ex∣plains, I say, this Supposition by the Simily of a Boat falling down a River, which goes on much slower than the Water that flows under it: A plausible comparison at first sight, but that has nothing solid in it: Since the reason of the Boats tardy Motion in respect of the Water that for∣ces it along, is wanting in the Planet, steer'd in the midst of the Celestial Matter. The reason is this, that part of the Boat, which stands a∣bove the Water, meets with the opposition of the Air, which bends its course differently from the Water, and consequently resists the Motion wherewith the Water influences the Boat. And the greater that resistance is, as in a contrary Wind, the slower is the Motion of the Boat, in comparison with that of the Water. And the less the resistance is, as when the Wind stands fair, the swifter is the motion of the Boat: But this is not to be found in the Planet, plung'd in the midst of the Celestial Matter: It pre∣serves intirely all that Motion the Celestial Mat∣ter can impress upon it, free from all external Opposition. Besides, being of it self indiffe∣rent to Motion, or to rest, to such or such a de∣gree of Motion, or this or that Determination, it offers no resistance, as M. Descartes himself speaks to the Matter of the Heaven.

He gives next the reason of that inequality of Motion of the Celestial Matter, and of the Planet carried by it; which is (says he) that though such little Bodies, as are the insensible parts of the Celestial Matter, conspiring all together to act confederately against a great one, may be as prevalent as that; notwithstanding they can ne∣ver

move it in all respects so swift, as they are mov'd themselves; 'cause though they are uni∣ted in some of their Motions which they com∣municate unto it, they infallibly disagree in o∣thers which they cannot communicate. Either we are mistaken, or this is a meer Gipsy-talk, at least in relation to the Business we are upon; and one of these Slights of Hand, we have observ'd M. Descartes from time to time to make use of, designedly to blind his Reader, and to conceal from him the Lameness and Imperfection of a Conclusion necessary to his System; which he is well aware of, but is unwilling any one else should see. 'Tis but bringing some pretty sort of Comparison that may prepare the Mind, and sooth and tame (if we may so speak) the Ima∣gination of his Reader, though commonly it never comes up to the stress of the Difficulty; and then clapping on it for a Confirmation some abstracted Reason, that few either can or will take pains to understand, and the Business is done; fore-seeing that being half-gain'd al∣ready by the Comparison, they will easily sur∣render themselves to the least appearance of Truth, which he shall give them a glimpse of in his reason, that often is a meer fallacy at bottom. And as for this before us: What matters it, though the little Bodies, that drive on a great one, should have several Motions? What tho' they do not communicate all these several Moti∣ons, provided they have still Strength enough to force it on, that the Body makes no resistance, that they all combine, as we suppose, with M. Descartes, to communicate the Motion requisite, and that we conceive them all pressing on its Surface, so as to push it towards the place where

they are push'd themselves? For certainly in all these Circumstances, we must conceive it going at as great a rate as they.

And yet from a Principle so weakly establisht as this, he concludes, That the Celestial Matter ought to move the Planet round its own Centre, and constitute a little Heaven about it, to turn at the same time as the great one. But not now to controvert that Supposition, as poorly prov'd as it is, let us persue him in his reasoning; and to see if it be good, let us imagine the Earth T. as it were suspended in a Void, and let us fancy a Circle of Celestial Matter as thick as the Diame∣ter of the Earth, that viol••ntly rushing like a Torrent, carries it suddenly away: But as we suppose this Torrent to be swifter than the Earth, methinks without having puzzled our Heads much with the Rules of the Determinations of Motion, we might readily conceive it, upon its violent dashing against the Earth, to be immedi∣ately divided in two Parts or Arms, whereof one should run above, the other below it; and whether we conceive this Stream of an equal, or a greater depth, than the Diameter of the Earth, it would diffuse it self round its Surface, above, below, and on every side. Whence it follows, that it would impress no Motion on it about its own Centre, but would moreover deprive it of that Motion if it had one; all the Lines of the Torrent counterpoizing one another, and resist∣ing the Determinations they should meet with in the Earth contrary to their own.

Here ought to be the foregoing Figure, p. 278.

Now methinks in explaining these things thus, it is not a bare Similitude that we offer, but a

perfect Idea of that which ought to happen in the Motion of the Celestial Matter, wherein the Earth is carried round the Sun,

Wherefore then will Descartes have the Cele∣stial Matter that carries the Earth, and insists a∣gainst its Superficies towards A, making greater haste than the Earth, bend its whole Current from A to B, not suffering half of it to run from A to D? For 'tis impossible for things to be, or to be conceiv'd otherwise. But if it ought to fall out thus, as questionless it ought, the Earth no longer-has a Vortex; since the Matter flowing from A to D, prevents that which flows from A to B from returning by C. D. Nothing can be more plain and evident than this Demonstration.

But let us suppose per impossible, that the Mat∣ter when arriv'd at A, should entirely make a double, to run towards B. Would it make a Vortex? No by no means. For advancing from B. to C. and arriving at C. it ought to deviate from the Centre of its Motion, and continue its Progress towards Z. The Reason given for it in the Principles of Descartes, is, That▪ this is the very place in all the little Circle it had begun to describe, where it finds least resistance. First, because the Matter it meets in that same Point is already on its Motion towards Z. and freely re∣signs its place. Secondly, because that which is below it, that is to say betwixt D. and C. resists it, and hinders its Descent, being more weighty, according to M. Descartes. And thirdly, because the Circle C Z. is its natural place, according to the same Philosopher. It will flow therefore more to∣wards Z. than D. and consequently make no Vortex.

But let us farther suppose a Vortex made, and the Matter continuing its round, from A. to B.

from B. to C. and from C. to A. would this Vor∣tex last? Not at all. For we must suppose one of these three things: Either that it is stronger than the Vortex of the Sun, that is, its Matter has a stronger bent and tendency from its Centre, than the Matter of the Sun's Vortex has from his, or that it is weaker; or that they both are equal. If it is weaker it must be destroy'd by the Vortex of the Sun. If stronger it must ruin his. It re∣mains then that its Strength be equal with the Suns: And M. Descartes must unavoidably sup∣pose it: But how will he prove it to us, I say not by a Demonstration (we will not put him on so hard a Task) but how will he bring the least Conjecture to give this Supposition a pretence to probability? Cannot we on the other side pro∣duce several Reasons to destroy this Supposition? Cannot we shew, in case the Vortex of the Earth was as strong as that of the Sun, and the little Glo∣bules wrested themselves as forcibly from the Cen∣tre of their Vortex, that the Earth it self would appear a Sun▪ and so would Iupiter to boot? Since that which makes the Centre of a Vortex to us seem luminous, is only the vehement Motion of its Matter? Though Descartes says the Centre would be drain'd of all its Matter, might not we however, imitating the Stile of that Philosopher, compare the Vortex of the Sun quite from S. to D. to a vast Ocean, whose boystrous Tide swel∣ling against the Stream of a little River, by which we illustrate the Vortex of the Earth, obli∣ges it to fall back again, and adds a Determina∣tion to its Waters quite contrary to its former? But with Descartes for a Vortex to be destroy'd, and for the Matter of the Vortex to take the Mo∣tion and Determination of another, is one and

the same thing. Let M. Descartes but prove his Vortex of the Earth with the least part of the rea∣son we have brought against it, or by as natural a Comparison as we have us'd to demonstrate it a meer Chimera, and he need not fear to stand the Test, Sallies and Assaults, of the best of his Adversaries.

What now if we should fall to examining the Difficulties that may be gather'd from the little Planet in particular, I mean the Moon consider'd in the petty Vortex of the Earth? Should we probably find less Matter of Objection?

Here ought to be the foregoing Figure, p. 278.

We advance no more than this, that suppo∣sing the Moon when arriv'd at A. was carried on towards B. she ought to deviate from her Vortex in C. For first, That's the external Superficies of the little Vortex, as M. Descartes will not deny. Secondly, She Attempts to leave her Vortex, by his grand Principle of circular Motion. He pretends she cannot make her escape towards B. because the Matter of the Solary Vortex in that place is more light and active, and repels her towards the Centre. Nor can she, according to him, make downwards towards K. for that, says he, the Celestial Matter on that side is hea∣vier than the Moon, and equally opposes her Descent: But we say she will get out of her Cir∣cle at C. and continue her Progress toward Z. For being in C. she finds no resistance, since the Matter of C. Z. is that of her own Circle, which is already on its March, and willing to give up its place. Besides, being in that place, she actu∣ally makes an Attempt to get rid of the Centre

of her Motion, that is to say, of T. she therefore will accomplish her escape, since there is no Ob∣stacle in that as is found in the other Points; and being cast out of her Circle, she will be oblig'd to continue her Journy towards Z. by the Mat∣ter plac'd above, and below her in the Circle, for the self-same Reasons as are given by M. Des∣cartes.

Yet in spite of all this, it cannot be deny'd, but that M. Descartes had good reason to order his Suppositions of these things as he did. His System was too far advanc'd to think of stop∣ping at so small an Obstacle as a Moon. All the Grandee-Planets were plac'd severally, according to the Quality and Preeminence their Solidity had given them. Madam Luna too was seated in the Circle of the Earth. There was only one little Inconvenience in the case, which was, that she must necessarily take a turn about the Earth, and consequently must be sometimes in the Earths own Circle, and sometimes out of it. She must therefore have a little Vortex of her own. And this is the best, as also only reason that can be given for his making one on purpose: And setting this aside, the Laws of Staticks alone could never have prevail'd with his Frugality, to put it self to that extraordinary Ex∣pense.

We had not insisted so long upon this Article, had not we consider'd it as the capital Point in the Cartesian System; and as the Founda∣tion of that prodigious Edifice, which has been taken in our days by so many, for the compleatest Mastery of a Human Mind. Let us see the Importance of our Demonstration by the Corollaries drawn from it.

Consequences of the preceding De∣monstration.

The first Consequence belongs to Astronomy and the Phenomena of the Planets. For first of all, there being no such thing as a Vortex, the Moon turns no longer round the Earth, since, accord∣ing to M. Descartes, the only reason of her cir∣cuiting is the Vortex that carries her aloft. Se∣condly the four Satellites of Iupiter, must be cashier'd of their Dignity and Employment, which they only injoy on account of the conti∣nual Centry they keep about him, and that by means of a particular Vortex attributed to that Planet, as well as to the Earth, in the grand Vor∣tex of the Sun. For all that we have said of the Vortex of the Earth and of the Moon, ought to be apply'd to Iupiter and his garde du Corps.

These two Particulars in Astronomy are consi∣derable enough to assure us that the World of M. Descartes is not that of Gods own making, which we live in, but of a very different Archi∣tecture and Contrivance.

The second Consequence respects almost all the principal Phenomena's of the lower World in general, whereof wee'l only concern our selves with the most considerable and easiest to be un∣derstood. 'Tis by the means only of the Vortex of the Earth, that the Cartesians, following their Master, explain the gravity of Bodies, and ac∣count for the Motion which they have towards the Centre of the Earth. For to instance, say they, when you cast a Stone up in the Air, it forces below it a Mass of the second Element, and Air equal to its bulk: But that same Mass has a far

greater agitation, and is better dispos'd for Mo∣tion, and consequently has more power to spring fromward the Centre of its Vortex than the Stone that scarce contains any thing but the Matter of the third Element; and therefore must be compell'd by the Matter of the second, to de∣scend towards the Centre of the Vortex, which is to say, the Centre of the Earth. We may tru∣ly say then, that without a Vortex heavy Bodies would not fall downwards, on the contrary they would naturally fly upwards, and thus we should see Miracles and Wonders.

According to the new System, the Sun as far out of Gun-shot of the Earth as he is, could not warrant his own Security, in case there should be a People that inrag'd at the heat and scorch∣ing of his Rays, should sometime joyn to give him an innumerable flight of Arrows. For these Arrows shot from the Earth, against the Sun, would fall in the circumference of his Vortex, and in the midst of the Matter of the second Ele∣ment, which strugling all it can to get farther from the Centre of its Motion, would constrain the Bodies less capable of Motion than it self, to descend towards the Centre, that is to say, the Sun. Now these Arrows would be Bodies far less capable of Motion than the Matter of the se∣cond Element, therefore it would constrain them to fall towards the Sun: Undoubtedly a very surprizing thing. And now we may easily give a reason for the Experiment that Father Mersen∣nus formerly assur'd M. Descartes he had made; that in discharging a Musquet perpendicularly towards the Zenith,* 1.3 the Bullet never came down again; for it must have infallibly been carried to the Sun.

According to this System, when we have a mind to make a Voyage, I do not say to the Globe of the Moon as did Cyrano de Bergerac, but to the Sun it self, it will be the easiest thing to be accomplish'd of a thousand. We need but turn our Head perpendicularly towards the Sun, then give a little Spring to put our selves in Motion, and to make room for the Matter of the Solary Vortex, that would come bounce against the Earth, to give our Heels a hoise, and this is all; For, according to the Principles of Descartes, it would give us such a flirt, as in a trice would dart us to that Luminary. In short, heavy Bodies would no longer make towards the Earth, but all would be upon the gallop to the Sun.

What shall we say of the Flux and Reflux of the Sea; which is one of the choisest places in all M. Descartes Philosophy, and on which account there's no one but ought to lament the Misfor∣tune of the Vortex? For by the assistance of that Vortex, M. Descartes and M. Rohault speak Marvels upon that insearchable Phenomenon of Nature. Which not only depends upon the Vortex it self, but upon the very Figure of it, which was made oval on purpose, and singularly for it, though probably it was not at first in the intention of the Philosopher. For never did Tragick Poet better and more artificially prepare the Incidents of his Piece, than M. Descartes has contriv'd his Conclusions. It would surprize one to see, in his deducing them, that one word, which he let fall careless by the way, and one would think without Design, should have been big with such an Infinity of Delicate Conse∣quences. A Man wonders in the third part of his Principles, to see the figure of that Vortex,

which is no better grounded than the Vortex is it self: But when in the fourth he sees the ne∣cessity M. Descartes had of it, to explain the Flux and Reflux of the Sea, he cannot choose but commend his Foresight and Precaution. Not but that, for all these pretty and specious Expli∣cations of the Phenomena of the Flux and Re∣flux of the Sea, the Cartesian System may be de∣monstrated false in that very Particular. We are convinc'd of this by those Reflections and Observations we have drawn from the best Ma∣thematicians since M. Descartes's time. They de∣monstrate by the Observations of the Distances of the Moon, determin'd by her apparent Dia∣meters, that that Planet is as remote in many of her Conjunctions and Oppositions, as in some of her Quadratures, and as near in some of her Qua∣dratures, as in several Conjunctions and Oppositions. Hence it is false that the Apogy of the Moon is al∣ways in her Quadratures, and the Perigy in her Conjunctions and Oppositions. Wherefore it can∣not be suppos'd that the Moon being in Conjun∣ction and Opposition, is always in the little Diame∣ter of the Elliptick Vortex, and in her Quadra∣tures always in the great one.

And yet it is upon this only Supposition that M. Descartes explains, and can explain, the ine∣quality of the Tides in the Conjunctions and Op∣positions, and in the Quadratures, as also of those we see in the Equinoxes and Solstices.

Again, if when the Moon pass'd our Meridian, the pressure of the Air was remarkably so much stronger, than in an other Hour of the Day, it would be perceivable by the ordinary Experi∣ments of Torricellus his Tube. Yet this diffe∣rence has never been observ'd, though it must be

very great: We could still give many other weighty Reasons against this System: But let it be how it will, take away its Vortex, and the Flux and Reflux must needs follow it.

Lastly, according to M. Descartes it is the Ce∣lestial Matter of this Vortex, that having more Motion than is necessary to turn in twenty four Hours time about the Earth, imploys the re∣mainder to diffuse it self all manner of ways, and together with the Matter of the third and first Element causes that great variety of Effects and Bodies which we so much wonder at. So the Vortex being ruin'd, all goes to Wreck and Confusion, and returns to its Native Chaos. Wherefore it makes not only for the glory of M. Descartes, but for the Interest of all Man∣kind to save this Vortex. For what remains, we protest we should be wonderful glad to see the Solution of the Difficulties we have pro∣pos'd against this and the other Points, upon which we shall resign our selves intire and sincere Proselytes to Cartesianism.

But in answering us let no one think to put upon us, nor quote a place in M. Descartes, to convince us he has not contradicted it in ano∣ther; when 'tis a plain and notorions Case. That Wheedle might take with those that have but perfunctorily read his Works, but must shew them the Contradiction in a clearer Light, that shall take pains to compare the opposite pla∣ces. We farther desire succinct and neater Answers, than the generality of those himself hath formerly given to those many Objections, propos'd against his Metaphysicks. Those very Answers raise in our Minds more Scruples than they cure: And yet because they have been

Printed, set off and tinsell'd with High-strain'd Praises of the Author, because he gives them a Magisterial and usually a disdainful Air, and we never see any Replies affix'd to them, many are habituated to reverence them as second Oracles, wherewith he hath confirm'd and explain'd those former of his own pronouncing. We shall not be such tame Asses, as to be impos'd on by M. Descartes's Reputation and Authority, no more than we would be Vassals to the esteem we have for some of his Disciples. We praise and highly approve the Advice he gives those who are on the Inquest after Truth, to beware of Prejudices, and shall put in Practice. These, Monsieur, are the chiefest of the things contain'd in my Peripatetick Memoir. They added some few others by word of Mo••th, as for Instance; That you would have been most horribly pester'd if any one would have track'd you step by step, in the fourth Part of your Book of Principles, especially from Number 32. to 45. where you are so particular, in posturing and disposing those parts of the third Element, of which you form your Earth: That there were many things there unsatisfactory to the Mind, and that there was not a Page wherein it might not be reason∣ably again and again demanded, why such a thing ought to be rather so than otherwise, with∣out your being able to give a tolerable Reason for it: That they believ'd that piece of your Physicks was one of those that had most con∣tributed to make your Philosophy pass with ma∣ny for a perfect Fable, ill-digested and not well hung together: And that your Adversaries, without troubling themselves to refute the Pro∣positions that you make there, the Discussion

whereof must needs be very tedious, had no more to do, than to refer your Readers to the place, to make them as ill-satisfied with you as can be wish'd.

[illustration]

They proceeded farther to say, you us'd to at∣tribute Properties to your Elements, which you was sure to take away again when they were not for your purpose. They gave me an Instance in the Matter of the first Element: You attribute as a Property to that Matter a great facility of division and readiness to change its Figure, so as easily to insinuate its self in every place, and fill all sort of Space whatever. But when 'tis brought for the Explication of the Nature of the Loadstone, that Propriety growing disad∣vantagious, Descartes thinks fit to change it for a contrary. There is occasion for a little Vortex of chamfer'd Matter round the Earth, and about each particular Loadstone, to give a Reason for

the Qualities of that miraculous Stone.* 1.4 These chamfer'd parts belong to the first Element. It formerly was nothing to them to accommodate themselves with the Figure of a Skrew, to pass and repass betwixt the Globules of the second Element. And now in issuing from the Earth, or from a Loadstone, the parts of Air are able to detain them. Instead of breaking and pro∣portioning themselves to the Figure of the Parts of Air, and second Element mingled with it, they flock and settle in heaps about the Earth and about the Loadstone, where they constitute a Vortex. Those that enter by the Southern Pole are incapable of passing by the Northern, since their Figure can no longer be adapted to that Passage; and they farther demanded, upon that occasion, how it was possible those Snail-work'd Parts, confin'd and stopt thus in a definite Space, having an intricate and confus'd Motion, one a∣mongst another, approaching the Pole of the Earth, or Magnet that was proportion'd to them, could so conveniently turn themselves an end, and present so cleverly their Point against the Pores, in order to their entrance in those Bodies. They pretended the contrary was more likely, and that generally the parts would present them∣selves across, and thereby make a Confusion ca∣pable of stopping all the rest, and damming up the Pores of the Earth and Magnet, so as to fru∣strate all those admirable Effects we see there. They advanc'd one Paradox more, which was a good Humour enough. Hitherto, said they, the most rational Philosophers have acknow∣ledg'd, that no Physical Argument could be brought against Copernicus, to prove the Earth was not turn'd about its Centre. But M. Des∣cartes

who sides with that Astronomer in his Hy∣pothesis, has furnish'd us with a very conclusive one against that Motion. His topping Princi∣ple is, That every Body circularly mov'd, at∣tempts to wheel off the Centre of its Motion: This Principle is true: He thence concludes, that the Earth turning on its Axle, would fly in Pieces, unless the Bodies, of which it is com∣pos'd, were closely press'd, and squeez'd against one another by the Matter of the second Element. This Consequence is moreover evident in his System: But now let us see if that pressure of the Matter of the second Element is strong enough to overpower the Effort which the Parts of the Earth make to disengage themselves and get fur∣ther from their Centre. This difficulty, said they, falls only on M. Descartes: For the School-Opinion is so far from owning such a Propensity in the parts of the Earth, to deviate from the Centre, as to suppose a quality and inclination that naturally buckles them unto it. Now upon comparing the pressure of Terrestrial Bodies one against another, by the Matter of the second Element, with the Effort Terrestrial Bodies make to get far off the Centre, the Effort must surmount the pressure: For the Effort is as great as the Motion that causes it, and the Motion is very great indeed, that can carry the Earth seve∣ral Leagues each Minute; and on the contrary, Experience shews there needs but a very little Effort for the conquering the pressure, since no greater is requisite, than that a Child of four years old imploys in Walking, to lift his Foot and separate it from the Ground, whereto the pressure of the second Element did fasten it. Wherefore it seems to be reasonably concluded,

That the Earth turns not on its Axis, since if it did, we should all be hurl'd in the Air, pur∣suant, to M. Descartes's Principle, which yet at bottom is true in sound Philosophy. Thus this System affords an excellent Argument against that of Copernicus.

They yet farther observ'd to me some peculiar Places and Points of your System, of the great∣est Importance, which you advance, as they pre∣tend, not only stript and naked of all Proof, but against all Reason in the World; they particu∣larly intreated me to read considerately and without prepossession, the second Number of the fourth Part of your Book of Principles, where ha∣ving explain'd how the Vortex of the Earth was destroy'd, and how there grew round that cak'd and crusted Star, a spacious Fleece of Air, you not only plunge it a great depth in the Solary Vortex, but also make that Sphere of Air keep pace, and wait upon it thither, and ever incom∣pass it as it still descends. They pretend that Supposition which you throw in Gratis, and without all Confirmation, is inconceivable; and yet if it be false, it were impossible at present to have Air about our Earth: It is inconceiva∣ble, say they: For, according to M. Descartes, the Air is nothing but an heap of the Parts of the third Element, exceeding small, and very loose and disunited from each other, and extra∣ordinary obsequious to the Motions impress'd on them by the Globules of the second Element, in which they swim. But this being so, how comes it to pass the Earth, traversing those im∣mense Spaces quite from its setting out, at the brink of the Solary Vortex, to the place in which it is, should still so preserve all the Air about it?

How by the Principles of that Philosopher could that Mass of Air, being far less solid than the Mass of Earth, have the same Motion, the same Determination, and same Swiftness as the Earth? How chance those little Parts so loose and inde∣pendent of each other, and so obedient to the Motions of the Celestial Matter, have not been dispers'd by the rapidness of that Matter, which they stemm'd, as the Dust is scatter'd by the Wind? But added they, how is this Mass of Air at present driven along with the Earth by the Celestial Matter? How has it all the same Motions? Is it against the Body of the Earth, or against the Globe of Air the Celestial Matter presses, to give both one and the other a Diurnal and an Annual Motion? Would not a Copernical Cartesian be hard put to't to unperplex himself of this Affair?

I omit, Monsieur, many other Difficulties whose Solution probably I may find in the An∣swers your Goodness will, I hope, vouchsafe the others I have already noted in this Letter. But for what remains, I desire you to take the earn∣estness wherewith I write to you, as an effect of that passionate Love you have inspir'd me with, of Truth, and especially to put a favourable Construction on my meaning. I have only tran∣scrib'd your Adversaries Memoire in their own proper Terms and Language, and I presum'd the respect I ow'd you, could not warrant my concealing or dissembling their insulting way of arguing. Which will serve to let you know how much it is for my Interest, and the Honour of our Sect, not to suffer them to triumph long.

The great and important Business, the pro∣duction of a new World at present finds you, joyn'd to the indifference you have always had, and still have more than ever, for the Opinions and Thoughts of Men, might reasonably make you neglect and despise these mean and trifling Things. But those extraordinary Instances you have given me of your Favour, encourage me to hope you will have some Consideration of my Honour, and will not deny me your Hand to raise me from the Ground, where I must own my self a little foil'd and disheartned. I desir'd the Reverend Father Mersennus to imploy his Credit with you, to obtain this Favour, and at once to assure you, as I here do, with all the Sub∣mission and respect I am capable of, that I am with all my Heart and Soul,

MONSIEUR,

Your most humble, and most obedient Servant, and most zealous Disciple.

Notes

• * 1.1

  Numb. 23.
• * 1.2

  P. 3. Prin. cip. numb. 100.
• * 1.3

  Let. 3. Tom. 2.
• * 1.4

  Part 3. princip.